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The biological use of sulfur as an alternative to carbon is purely hypothetical, especially because sulfur usually forms only linear chains rather than branched ones. (The biological use of sulfur as an electron acceptor is widespread and can be traced back 3.5 billion years on Earth, thus predating the use of molecular oxygen. [28]
From the sulfide they form the amino acids cysteine and methionine, sulfolipids, and other sulfur compounds. Animals obtain sulfur from cysteine and methionine in the protein that they consume. Sulfur is the third most abundant mineral element in the body. [21] The amino acids cysteine and methionine are used by the body to make glutathione.
Most of the sulfur oxidizers are autotrophs that can use reduced sulfur species as electron donors for CO 2 fixation. The microbial oxidation of sulfur is an important link in the biogeochemical cycling of sulfur in environments hosting both abundant reduced sulfur species and low concentrations of oxygen, such as marine sediments, oxygen ...
Biochemistry, or biological chemistry, is the study of chemical processes within and relating to living organisms. [1] A sub-discipline of both chemistry and biology , biochemistry may be divided into three fields: structural biology , enzymology , and metabolism .
Sulfur is contained in the amino acids cysteine and methionine. [3] Phosphorus is contained in phospholipids , a class of lipids that are a major component of all cell membranes , as they can form lipid bilayers , which keep CO2 , proteins , and other molecules where they are needed for cell function, and prevent them from diffusing into areas ...
Phosphorus and sulfur are also common essential elements, essential to the structure of nucleic acids and amino acids, respectively. Chlorine, potassium, magnesium, calcium and phosphorus have important roles due to their ready ionization and utility in regulating membrane activity and osmotic potential. [2]
Sulfur assimilation in microorganisms is regulated by a variety of environmental factors, including the availability of sulfur in the medium and the presence of other nutrients. The activity of key enzymes in the sulfur assimilation pathway is also regulated by feedback inhibition from downstream products, similar to the regulation seen in plants.
Sulfur reduction metabolism is an ancient process, found in the deep branches of the phylogenetic tree. [15] Sulfur reduction uses elemental sulfur (S 0) and generates hydrogen sulfide (H 2 S) as the main end product. This metabolism is largely present in extreme environments where, especially in recent years, many microorganisms have been ...